This invention relates, in general, to integrated circuits, and more particularly, to external interconnect bonding to a connection point of an integrated circuit.
In general, an integrated circuit typically has an array of metal pads or connection points for external coupling from the semiconductor die. The metal pads or connection points couple signals into and out of an integrated circuit. An example of an external interconnection to an integrated circuit is a wire coupling a metal pad of the integrated circuit to a lead of a lead frame. The wire electrically couples the wire to the lead. A combination of pressure and heat allows the wire to bond or adhere to the metal pad. Applying heat during a wire bond process increases the adhesion of a wire to a metal pad. The leads of a lead frame package couple the integrated circuit to circuitry external to the semiconductor package.
The conductive bump technology used in a multi-chip module is another type of external interconnection for electrically coupling to an integrated circuit. A multi-chip module typically interconnects a number of integrated circuits via a common substrate. The common substrate has metal pads or connection points that align to connection points of an integrated circuit. In general, a solder bump or other conductive material is formed on the connection points of an integrated circuit, the common substrate, or both. The integrated circuit is electrically coupled to the common substrate by aligning the integrated circuit to the common substrate and heating the structures until the conductive material on each connection point flows thereby coupling connection points of both the integrated circuit and the common substrate. The conductive material physically and conductively attaches the integrated circuit to the common substrate. In both wire bond and conductive bump interconnect the entire integrated circuit is heated which subjects the semiconductor die to temperatures that could damage the circuitry. Also, the heating process is not easily controlled and increases manufacturing costs.
It would be of great benefit if a structure and process could be provided that reduces the cost and manufacturing complexity of providing external connection to an integrated circuit.